Kazakhstan's massive Kashagan oil field will not produce any oil this year and might not start production until 2016.

The North Caspian Operating Company that runs the Kashagan project said on April 28 preliminary indications from recent testing of underwater pipelines shows those pipelines need to be totally replaced.

Kazakhstan's Minister for Economy and Budget Planning Erbolat Dossaev said he expected production to start late next year at the earliest.

The two 90-kilometer pipelines leading from the Caspian offshore site to Kazakhstan's mainland started leaking shortly after the long-awaited start of operations last September.

Toxic gas from the oil corroded the pipelines and caused them to start leaking and production was suspended.

Kashagan contains some 13 billion barrels of recoverable oil but the project is a decade behind schedule.

The cost of developing the site has risen from the original estimate of $50 billion to $135 billion.